DNS considerations associated with migrating to a new MailEnable installation


An important consideration in migrating to a new e-mail server is the transition of the flow of e-mail to the new e-mail server. This article outlines important considerations regarding DNS/Mail Exchanger configurations associated with such the transition from one e-mail platform to another.


The key to a successful migration is the transition of DNS/Mail Exchanger records to ensure e-mail is received by the new mail server installation.

Scenarios for consideration are outlined below:

Approach 1: IP Address Swapping
The simplest approach with migrating is to install on a new server, then to simply change the IP address of the new server to have the IP address of the original server.

For example:

  1. Install MailEnable on the alternate server
  2. Migrate all user accounts/domains/addresses from the existing (legacy) e-mail server to the new MailEnable installation.
  3. Change the IP address of the original mail server to another IP address (you may need to ask the data center to provide you with a temporary one).
  4. Change the IP address of the new MailEnable server to be that of the original mail server.
  5. At this stage, any new e-mail will be received by the MailEnable server, since it now bears the IP address of the former server. As such, you can begin the process of migrating e-mail from the former system to the MailEnable system.

Approach 2: Concurrent Installation

An alternate approach is to install MailEnable on the same server as the existing (legacy) e-mail server. There will of course be conflicts for the ports that are used by MailEnable and as such, the Windows Service control manager should be used to stop all MailEnable Services (i.e. ensure that the MailEnable SMTP Service, POP Service, IMAP, etc are all stopped. Once MailEnable is installed on the server, configure the service start parameters to be 'manual'.

Then migrate any user/address/domain settings accordingly.  Once the settings have been migrated, stop the old e-mail server service and enable/start the MailEnable services. Then migrate user e-mail into respective MailEnable mailboxes.

Approach 3: Migration of DNS records through 'Smart hosting'

If Approach 1 or 2 are not possible, then the only remaining migration approach involves transitioning DNS records. It can take up to 48 hours (or possibly longer) for these changes to become effective, therefore, provisions need to be made for the fact that e-mail will/may arrive to both the old mail server and new e-mail server.

In this case, the best approach is to have the existing e-mail server to forward/pass on e-mail to the new e-mail server. This configuration is normally called smart hosting or domain forwarding. The respective domain/e-mail addresses/mailboxes need to be configured on the target MailEnable server to ensure that any redirected e-mails are received. Whilst this redirection is in place, you can then migrate e-mail from the mailboxes of the old e-mail server to the intended MailEnable e-mail server.


For more information on DNS, and how it relates to the delivery of e-mail please refer to: http://www.mailenable.com/kb/content/article.asp?ID=ME020019

Product:MailEnable (All Versions)
Class:TRB: Troubleshooting (Configuration or Environment)
Revised:Wednesday, May 4, 2016